Panzerserra Bunker- Military Scale Models in 1/35 scale: Churchill 3 inch 20CWT gun carrier

Churchill 3 inch 20CWT gun carrier - case report

Lads!!

This is one of the weirdest versions of the Churchill infantry tank: the Churchill 3 inch 20 CWT gun carrier. Let's get to know this ugly (and powerful) example from the famous Churchill family.

Churchill 3-inch gun carrier at the Armoured Fighting Vehicle School, Gunnery Wing
Lulworth in Dorset, England - 25 March 1943

History:

Although the British Army had developed self-propelled artillery during the WWI, and used it to some extent, the concept did not prove popular in the military. A few experimental vehicles, known as Birch Guns, were produced after the war but by the end of the 30's there was no perceptible interest at all and no prototypes to provide inspiration for more models.

Birch Gun Mark II in British Army manoeuvres. In service from July 1926 to June-July 1931.
20 Battery, 9th Field Brigade, Royal Artillery.

By 1940, the concept of self-propelled artillery was up for consideration again, but with two quite different objects in view. The Royal Artillery was interested in obtaining self-propelled mounts for two of its weapons, the 25-pounder field gun/howitzer and the 6-inch howitzer. The 25-pounder version originated the Bishop, a self-propelled artillery vehicle based on the chassis of the Valentine infantry tank., but the 6-inch vehicle was only in the realm of conjecture. The 6-inch project was finally cancelled in December 1941.

The other self-propelled gun project was quite different: It was born of the desperate need to find a weapon powerful enough to defeat German armour in the dark days of a possible Nazi invasion. No one was expecting a sophisticated weapon system, which might take years to develop but all they wanted was a quick and effective means of transporting the powerfull possible anti-tank gun on some sort of tank chassis, and that it was available as fast as possible... But which gun?

The 2-pounder gun was "little" and weak ... The 6-pounder was still in development, as was the mighty 17-pounder... Nothing big and powerful was available immediately on those distressing days...

Specialists were consulted and they came up with the idea of using an anti-aircraft gun, firing a high muzzle velocity projectile, that would allow to penetrate any contemporary German armor. And the gun available at the time that fit these parameters was the 3 inch, 20 cwt AA gun.

3-inch AA gun from 303rd Battery, 99th Anti-Aircraft Regiment
Hayes Common, Kent, May 1940

The 3 inch AA gun dates from 1914 and it was common to both the Army and Royal Navy, so the stocks of guns and ammunition were good.

3-inch AA gun as surface gun in a British U-class submarine, Malta - April 1943

3 inch, 20 cwt AA gun - right side - preserved at Canadian Forces Base Esquimalt

3 inch, 20 cwt AA gun - left side - preserved at Canadian Forces Base Esquimalt

By 1940 it was slowly being replaced on land by a superb new QF 3.7-inch AA gun and there was no problem in providing 100 or more old 3-inch barrels for this self-propelled project.

3.7-inch AA gun of 127th Heavy Anti-Aircraft Regiment
Southwold, Suffolk, 9 October 1944.

Who first came up with the idea of using an anti-aircraft weapon as anti-tank weapon is not entirely clear, but we now know that German troops used their splendid Flak 88mm anti-aircraft gun against tanks in the Spanish Civil War in 1936 and again in France, against French and British armor, with devastating effects ... but it is very unlikely that anyone in Britain would have been fully aware of these details in 1940-41.

French Char B1 heavy tank destroyed by a Flak 88mm shell
killing all its crew. Deneé, France, May 1940.

The terror of the Allied tank crew: A German 88mm gun firing against tanks...
Russia - July, 1942.

However the performance of the British gun speaks for itself, and availability must have been another key factor. Firing horizontally the gun had a range of some 11.000 meters and firing a 5,67 kg armour piercing round, could penetrate 84mm of armour, at 30 degree angle. at 914 meters. The German 88mm was better, but it was larger and fired a heavier shell at a higher muzzle velocity (810 meters per second against 610 m/s for the 3") Compared with the American (618 m/s|) or British 75mm tank guns of 1942/ 43 (620 m/s) the 3 inch 20 cwt was very impressive indeed.

The project was authorised by the War Cabinet and the A22 Churchill was the best choice for a chassis. By the end of April 1941 it was learned that general arrangement drawings for the new mounting were more or less complete. Early in July a wooden mock-up was nearly complete. On 25 July 1941 a contract for 100 'Tanks A22 "Special Type" (Churchill 3" 20 cwt Self Propelled Mounting)' was issued in favour of Vauxhall Motors.

Churchill 3-inch gun carrier - Notice the side hull without extra-armour (and no conical bolts...)
and the early type track links...

Notice the triangle plate in the front armour, above the conical bolt:

It is a warning that the armour has not passed by tempering process.

The "soft" steel was only for training: characteristic of a non-operational vehicle.

In the incert, the "soft triangle" in an A39 Tortoise Super Heavy Assault Gun

The Director General of Tank Supply, announced that 24 of the guns should be completed as quickly as possible and within days the order had been officially signed for 24 machines. In January 1942 it was revised to 50: that is one pilot model and 49 production machines to be assembled by Beyer Peacock & Company of the Gorton Foundry, Manchester, a firm famous for constructing the huge Garratt articulated steam locomotives. Vauxhall Motors was spared to focus on the mass production of the normal versions of Churchill.

Garratt Class U1 articulated steam locomotive

All 50 vehicles were completed by November 1942 and issued with the War Department numbers S31273 to S31321. The first edition Instruction Book for this vehicle, published in August 1942, gives it the official title of Carrier, Churchill 3 in. Gun Mark I.

Churchill 3-inch gun carrier at the Armoured Fighting Vehicle School, Gunnery Wing
Lulworth in Dorset, England - 25 March 1943.
Notice the hull with conical bolts, the track links late type and
the WD number with correct prefix: S

The vehicle was little more than a standard Churchill hull with a large, box-like superstructure and the gun mounted low down at the front, to the left of the driver.

The frontal plate. which is a direct extension of the vertical driver's visor plate was 89 mm thick, with 76 mm at the sides and 15 mm on the roof. Overall weight is given as 39 tons; length 7.950 mm. (including gun) and height 2.768 mm. This was nearly a 304 mm taller than the Churchill I but it was exactly the same width.

The Churchill 3 inch gun carrier had a crew of four: The commander was positioned on the right side, and he was the only one with a roof hatch, or cupola. Its station is the most posterior, on the right side of the superstructure. On its left side, with a certain circulation space, is the loader, feeding the 3-inch gun with its shells stored on the sides of the vehicle (see chart). In the front right portion is the driver's station, in the normal position of all Churchill tanks. The worst position is for the gunner, who twists between the commander and the driver. He almost bends over the driver's position, commanding the gun's elevation and transverse levers, installed in the right portion of the gun.. The Churchill gun carrier's rectangular casemate superstructure was tight for the crew. Even more so because the 3 inch cannon was very bulky.

The 3 inch gun had maximum elevation of 15 degrees, depression of 10 degrees and traverse just 5 degrees either side of the centre line. Thus it was essential that the driver be in his place with the engine running whenever the Churchill was in action because lateral movement of the gun beyond 5 degrees was his responsibility, rotating the entire vehicle with its tracks.

Churchill 3-inch gun carrier - front view
Notice the "early/wrong" T prefix in the WD registration, the early tracks
but the hull now is full operational: There is no triangular "soft steel" warning plate.

Typical ammo stowage was 49 rounds of armour piercing shells (AP) and 16 rounds of high explosive (HE). There was no permanently mounted secondary armament but a Bren gun was stowed inside the crew compartment (and a Lakeman MG mount installed out, in the right side of the hull...) along with two Thompson sub-machine guns.

Notice the folded Lakeman MG mount installed in the hull
In the pic's insert, the Lakeman mount with Bren in position...

During an engagement the commander first selected his target by directing the driver, lining the tank up, using his external sighting vane. To assist this part of the process the driver had his own traverse indicator alongside his visor. Final target acquisition being taken care of by the gunner. Firing on the move was impossible since the gun itself was too heavy. When the Carrier was travelling the gun had to be locked in full elevation to prevent damage.

The Lakeman AA mounting for the .303-inch Bren machine gun, can be seen stowed
just above the circular pistol port in the vertical side plate of the superstructure.
Notice the 3-inch gun, is at full elevation, the position it would be locked in when the vehicle
was travelling, to prevent damage to the gun.

If, as the contract cards appear to show, the order for these Carriers was completed at the beginning of November 1942, they appear to have been emerging at the rate of about one a week, starting in May. One explanation of this might well be production problems but it is also reasonable to assume that they were, by then, a very low priority: the purpose for which they were designed had disappeared. The threat of an invasion of Britain had passed and, indeed, a substantial attack on occupied France was in the offing.
The question of what to do with the Churchill Gun Carriers must have been exercising some minds but documentary evidence is almost entirely lacking. Only one vague clue can be found in an entry in the War Diary of 14 Canadian Army Tank Regiment, otherwise the Calgary Regiment of 1st Canadian Army Tank Brigade.

By mid-1943, most of the Carriers were converted to standard tanks and some for ARVs (armoured recovery vehicles). However one Churchill gun carrier, at least, retained its superstructure and was used as a test vehicle to carry and launch 50 Snakes, the oversized version of the mine-clearing line charges Bangalore torpedoes. Some sources quote this version as Churchill Wurlitzer (band organ).

"Wurlitzer" Churchill gun carrier S32321 (the last Churchill Gun carrier built)
Used as test-bed for Snakes mine-clearing line charges
Notice the absence of the main gun

main font:

Specs:

Churchill 3 inch 20 CWT gun carrier
Type	anti-tank self propelled artillery
Place of origin	United Kingdom
Service history
In service	1942-43 (?)
Used by	United Kingdom Canada (?)
Production history
Designer	Vauxhall Motors
Manufacturer	Beyer Peacock & Company
Produced	1942
No. built	1+49
Variants	Wurlitzer Churchill
Specifications
Mass	39 t
Length	7.95 m (with gun)
Width	3.25 m
Height	2.77 m
Crew	4 (commander, gunner, loader/radio operator, driver)

Armour	102 mm hull front, 89 mm hull side, 51 mm hull rear, 89 mm casemate front, 76 mm casemate side and rear, 15mm top
Main armament	3 inches, 20 cwt AA gun with 65 rounds ammo
Secondary armament	none
Engine	Bedford 12-cylinder, 4 stroke, water-cooled, horizontally opposed, L-head petrol engine 350 hp (261 kW) at 2,200 rpm
Power/weight	9.1 hp (6.7 kW) / tonne
Transmission	Merritt-Brown 4-speed constant-mesh epicyclic gearbox
Suspension	Coiled spring
Operational range	90 km
Speed	24 km/h
Steering system	Triple differential steering in gearbox

The kit:

In our glorious days, if you want to have this beautiful machine in your collection, just buy the AFV Club Churchill 3 inch 20 CWT Gun (#AF35253):

AFV Club box art... Hmmm..IMHO, with a dubious and debatable aspect ...

But in the old and shady days, when dogs were being lashed with sausages, there was no easy and swift option... There was no wonderful Churchill family from the AFV Club ...The only Churchill in the market was the veteran Tamiya's Churchill Mk.VII (#35210). Wrong model and wrong chassi for this girl...

Tamiya's Churchill Mk.VII (#35210)

But "Modeling always finds ways to develop and prevail" !!! In the last century there was a resin conversion from International Models Asia (IMA) (today discontinued ...) which was the solution ...
And I just "committed" this heretical building!!

Beware of the following images: they are at least shocking !!!

The IMA resin superestructure for Tamiya's Churchill Mk.VII

The Tamiya's hull: in red the portions to be removed and in green, the parts to be modified...

The heresy is in progress!!!

The side view... The resin conversion it was very good!!

The Tamiya hull after surgery...

Correcting the top of the fenders...

Done!!

The IMA plastic templates for the side hulls...Notice the rectangular hatches
The screws are for a perfect alignment for the bonding of the parts ...

The cuts on the Tamiya's Mk.VII hull...

The girl is growing...

The IMA'sresin kit comes with exhausts broen...I did two with cooper tubes...

And the hull almost ready!! Notice the periscopes added to the top of the superstructure
as an artistic license (dar green) ... I was already crazier than I am today ...
The gun barrel was made with lathe, with a piece of brass.

The metal gun was done on a lathe, by a mechanic, my friend...
Notice the "soft armour" triangle, made with aluminium beer can

Rear view!!

3/4 front view. The aiming frame was made with cooper wire...

With primer...

Painting.... Disruptive cammo in black and green...

The weathering...

Washes...

Tow hook made with copper wire...

Rear deck...One exhaust pipe exposed...

Starting a Lakeman mount...

Ready...But in wrong shape...Old times!!!

The Churchill 3 inch Gun Carrier like a toy...a pitty!!

But as I am a fanatic beliver of the "Law of Conservation of Scale Model Matter" (Not Lavoisier's one, but Panzerserra's law...), which reads: "In modeling, nothing is lost, everything is preserved and transformed!", the time has come to bring this beautiful girl to a more "convincing" reality !!! She deserves it!!! First of all, lets rip off the old paint ... Caustic soda !! Be very careful at that time !!

Preparing a beauty bath !!

Corrosive flakes in a plastic bowl. The substance does not attack plastic or resin ...
But it corrodes yourskin ... Very careful with the contact and
the fumes that emanate of the substance !!

Adding water...At that time many toxic gases emanate...
This should be done in a very ventilated place ...
And a certain amount of heat emanates, in an exothermic reaction ...
Do not soak the kit yet ...

I had to change the basin ... The green one was very small ...
The red bowl allowed a complete immersion ... The mug is to keep the kit submerged ...

The paint begins to be corrupted by the action of the caustic soda ...
The bath can last for hours ... In my case, six hours ...

After 6 hours under the action of the alkaline bath, a vinegar bath, to neutralize the excessive alkalinity of the surface of the kit ... 30 ml of vinegar are sufficient for this ...

Vinegar (acid bath...) to neutralize the Ph.
If not, future paint can be attacked by soda residues ...

The green/black acrylic paint was removed, but not a base layer (which I had forgotten ..)
of paint with automotive enamel paint ... Holy shit !!!

The paint with automotive enamel is very strong for caustic soda !!

But it does not withstand the corrosive power of a automotive hydraulic brake fluid !!!
Notice the blue fluid attacking the yellow paint...

The paint being removed by the fluid and by an old toothbrush ...
Phew !! What a relief!!!

And the Churchye Girl, virgin again, after caustic soda and hydraulic fluid!!!

Sanding by improving parts with defects and irregularities ...

The pickling process was a success !!!

And since I was working with other Churchye girls, I started using AFV parts from my spare-parts box to upgrade the Tamiya girl !!! First of all, removing the periscopes, which did not exist in the original vehicle ... And I did not return the triangle of "soft armor" because my girl will be of the production type.

Notice the new parts from AFV Models Churchills: Commander hatch, air filters, hull's bolts,
auxiliary fuel tank and oil cans in the rear.

Details in close-up... Heil to AFV, which provides many extra parts in its Churchill kits ...
The aerias are acupuncture needles ...

New map tube in the side of the hull...
The hull bolts in right places...
My version will be the extra-armour one...

The Churchill 3-inch gun carrier and Churchill Mk. I CS reversed waiting
final details and painting...

Now, painting and marings...During the research on this girl, this photo caption caught my attention: It's showed a Churchill 3 inch gun carrier in training at the Lulworth Gunnery School, in Dorset, England!!

Churchill 3-inch gun carrier at the Armoured Fighting Vehicle School, Gunnery Wing

Lulworth in Dorset, England - 25 March 1943

As I love making my vehicles with a historical foundation, I wanted to place my girl in the real time and space ... and I drew these markings which, historically, may have been used. The serial number fits in the latest models, with extra armor in the hull and the coats and markings used by the vehicles when being tested at the School. The name GUINEVERE is totally fictitious, but I think it's totally appropriate for a "Naughty Queen" like is my girl !!!

Gentlemen, I present to you my beautiful Queen, GUINEVERE, a Churchill 3inch 20CWT gun carrier training their skills in Lulworth Gunnery School, Dorset - England, in the Spring of 1943.

Green as base paint... Notice the new Lakeman MG mount

Shades of green on my girl. I really like old school ...

Exhaust pipes under intense use...

The profile to guide me in the impression of my decals ...

As my printer does not print in white (it's an old Laserjet Color ...), I use white decals as backgrounds and transparent decals for colors and markings. The white letters and numbers I print in transparent decal sheet the numbers surrounded by colored margins as close as possible to the base color of the vehicle. Afterwards, I masked the numbers and/or letters and repainted the margins. It is laborious but it works ...

Notice the letters and numbers: white through the transparency printed in green.
Later, this weird green color will be repainted with the base color, masking only the area of the letters ....

Sealing the decals with Pledge, the "milk of the Mother Goddess."

Ater the matt varnish, starting the weathering. Notice the Bren gun in
the Lakeman mount...

Bren's round ammunition drum was made in scratch

Tools in place...

Front view...

And the girl was ready: this is GUINEVERE, a Churchill 3inch 20CWT gun carrier, working at Lulworth Gunnery School, Dorset - England, in the Spring of 1943.